The present invention relates to a machine tool of the type in which a plurality of gang heads different in type one from another are provided and any one desired is freely selected to be used.
As for this kind of machine tool, there has been hitherto known a type in which plural gang heads are provided on a stock yard comprising an annular rail and any desired one is selected therefrom to be used. With this type, however, it is comparatively troublesome to attach and detach the selected one in relation to the rail, and thus it involves the disadvantage that it requires comparatively much time and much trouble in replacing one gang head with another.